judy gash ber is with boston's dana farber cancer institute. >> i think this will have an effect on practice, and particularly for my young patients. i think they'll feel much safer for all of us. >> reporter: but there are significant side effects. most women have immediate effects of menopause including night sweats and hot flashes. still she says if her doctor recommends it, she'll take it again. >> recurrence is something you live with all of your life. all of a sudden you hear all these stories about women's cancer coming back after eight, nine, ten years, so it doesn't go away, no. >>> tamoxifen has other side effects including risk of uterine cancer, strokes, and blood clots. but researches say for younger breast cancer survivors, those risks are outweighed by the drug's benefit. elaine quijano, cbs, new york. >>> coming up next, your thursday weather and the hit song "gangnam style" hanging on big time. we'll be right back. anging on big time. we'll be right back. made a comm. bp has paid over twenty-three billion dollars to help those affected and to cover cleanup costs. today, the